Gaseous-fluid dynamometer



March 5, 1929. J. TRACY 1,704,412

GASEOUS FLUID DYNIIOIETBR Filed June 18, 1926 IN ENToR 5e-Fw @Aar I; TTgRNEY Patented Mar. 5, 1929.

UNITED STATES JOSEPH TRAUY, F RUTHERFGRD, NEW JERSEY.

' erasmus-FLUID nYnAnoMnTER.

Application led l'ime` 18,

My invention relates to a gaseous fluid dynamometer.

The fluid brake made use of in accordance with my invention is preferably a blower and desirably an air blower. Blowers of various forms can be used. A centrifugal blower comprising a fan provided with flat or club blades is well adapted for my purpose.

Fig. 1 is an elevational view of a dynamometer embodying the invention. Fig. 2 is a section on line 2-2, Fig. 1, and Fig. 3 is an end view.

Reference character 10 indicates the dynamometer stand which is provided with housings 12 for the anti-friction bearings 14. A gear casing 16 is provided with trunnions 18 mounted on the bearings 14 to turn freely on an axis coincident with the axis of drive shaft 20, which is to be connected with and driven 20 from the engine or the like to be tested.

The driven shaft 22. also mounted in casing 16, operates the blower fan, which may be of various forms. As shown the fan 24 comprises the fiat blades or paddles 25,25 se- 25 cured direct to shaft 22. Gearing in casing 16 communicates rotative movement from the drive shaft 20 to the driven shaft 22. Various gearing arrangements may be resorted to, but as shown, the spur gear 26 on drive shaft 30 20 meshes with a spur gear 28 on the driven shaft 22. The gear casing 16 is provided with the arm 30, having the downwardly directed knife edge 32 for exerting pressure on a scale The resistance imposed on the revolving fan 25 by the iuid in which it moves can be measured by measuring the reaction of the gear casing communicated to the scale 34 by the arm 30.

The blower fan 24 is preferably located in the housing 35 having a central inlet at 36 and an outlet 38. For controlling the extent of opening of inlet 36 and thereby the quantity of air admitted and the extent of braking by the blower, a slide cover 40 is provided moving in slideways 42 and is adjusted by the hand screw 44. 'When the extent of movement of arm 30 is small, as may be the case when the beam scale is being used, the housing 35 may be secured rigidly to the floor or the machine base, as by the legs or struts 46, the extent of oscillatory movement of gear casing 16 at the region where the shaft 22 projects therefrom being quite small. In making dynamometer tests, a very good range of load 1926. Serial No. 116,868.

When the fan or other rotary member proi vided with vanes and turning in a fluid medium is made use of without the blower casing, the apparatus is reversible and can be used with engines, for example, which rotate either clockwise or counter-clockwise. To provide for such reversal a second arm 30 may be provided, if desired.

It will be seen that a dynamometer embodying the invention can be simply and cheaply constructed and operated. Changes and modifications may be resorted to without departing from by invention, within the scope of the appended claims, by which I desire to include all that is novel over the prior art.

I claim:

1. In a dynamometer, a brake consisting of a gaseous fluid fan, a housing for the fan with inlet and out-let openings, and means for regulating the extent of inlet opening.

2. In a dynamometer, a drive shaft adapted to have a motive device attached thereto, a driven shaft geared to the drive shaft, a supporting member for t-he shafts and gearing mounted to pivot on an axis substantially c0- incident with the drive shaft axis, an air fan actuated from the driven shaft, a housing for the fan provided with inlet and outlet openings, and means for regulating the extent of inlet opening.

3. In a dynamometer, a drive shaft adapted to have a motive device attached thereto, a driven shaft geared to the drive shaft, a supportingr member for the shafts and gearing mounted `to pivot on an axis substantially coincident with the drive shaft axis, an arm extending from said supporting member and provided with a knife edge for transmitting torque moment to a scale or the like. an air fan actuated from the driven shaft, a housing for the fan provided with inlet and outlet openings, and means for regulating the extent of inlet opening.

4. In the process of measuring the torque of a motive device, the steps which comprise braking the device with a gaseous fluid blower, regulating the admission of gaseous fluid to the blower, and measuring the reaction of the blower.

5. In a dynamoineter, a gear casing mount- 5 ed to Jurn on en :iT-ais, a drive shaft at the gear easing axis adapted to have e motive device attached thereto, e second shaft mounted in the gear case, gearing in the gear oase operatively connecting said shafts, a rotor operated by the second shaft and adapted to turn 10 in a fluid element, means for varying the resistanoe to the Jaurning of the rotor, .and means for measuring the turning moment oi' the gear cese.

In testimony whereof, I have signed my 15 naine hereto.

JOSEPH TRACY. 

